tab replace to space 4

[황병희]

[i am writing question on comp.lang.python]

usally i write python code in gnu emacs on ubuntu 18.04 sometimes i
re-edit the code vim in same machine so often when i do run the code in
shell like as ./test.py i meet consol error -- which line wrong!

so i am considering how can i replace all tab to space 4 within python
code. if there is solution in google i am very sorry.

thanks all and any comments welcome^^^

-- 
^고맙습니다 _地平天成_ 감사합니다_^))//